Incidence and risk factors of allograft bone failure after calcaneal lengthening

Calcaneal lengthening osteotomy using ipsilateral fibular graft in the treatment of flexible flatfoot deformity: preliminary results

PURPOSE

Flexible flatfoot deformity is quite common among adolescents. This study aimed to report the preliminary results of calcaneal lengthening osteotomy using a fibular bone graft.

METHODS

This single-center, retrospective study included 28 patients (28 feet) with symptomatic flexible flatfoot deformity. The deformity was corrected with calcaneal lengthening osteotomy using an ipsilateral fibular graft. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot score at the final follow-up was selected as the primary outcome measure. Radiographic outcomes included the anteroposterior talo-first metatarsal (AP talo-MT1) angle, the lateral talo-first metatarsal (LAT talo-MT1) angle, the lateral calcaneal pitch (LCP), and the Goldberg scoring system (GSS) for fibular graft incorporation. The visual analogue scale (VAS) was used to assess pain over the ipsilateral fibula donor site.

RESULTS

The AOFAS ankle hindfoot score improved from a mean of 53.7 ± 22.4 to a mean of 81.1 ± 19.8, the AP talo-MT1 angle improved from a mean of 24.1° ± 15.6 to a mean of 12.9° ± 7.3, the LAT talo-MT1 angle improved from a mean of 22.3° ± 3.2 to a mean of 7.9° ± 2.3, and the LCP improved from a mean of 10.1° ± 7 to a mean of 24.4° ± 9.1. The GSS was seven points in all patients, which indicated complete radiographic union with an excellent reorganization of the fibular bone graft. The VAS for pain over the ipsilateral fibula donor site was zero at the final follow-up.

CONCLUSION

The fibular bone autograft achieved excellent incorporation when used in calcaneal lengthening osteotomy with good improvement in the clinical and radiographic outcomes in patients with symptomatic flexible flatfoot deformity.

LEVEL OF EVIDENCE

III, Therapeutic study.

Preliminary Outcomes of Calcaneal Body Lengthening for the Calcaneus Shortening

For lengthening irregular bones, such as calcaneus, there are few reports in the literature. This study aimed to introduce the treatment strategy and preliminary outcomes for calcaneus shortening using calcaneal body lengthening. From January 2017 to January 2022, calcaneal lengthening was conducted for three patients (two males and one female) who suffered from traumatic calcaneal shortening. The Achilles tendon was lengthened in one patient. After osteotomy of the calcaneus, an Ilizarov frame was used to gradually (1 mm/day) distract the calcaneal fragment. The lengthening procedure was stopped when the calcaneal height and length were restored based on radiography. The fixator was removed after bone union. The average follow-up length was 18 months (range, 14-24 months). X-ray was used for radiological assessments. Patients reported satisfaction using the 100-mm visual analog scale (VAS). Clinical outcome was evaluated following the American Orthopedic Foot and Ankle score. All data were assessed by two physicians blind to clinical assessments. The wound healed primarily in three cases. The bone got solid union without refracture and malunion. The distraction time was 30 days (range, 25-45 days). The fixation time was 113.3 days (average, 80-150 days). Calcaneal lengthening was 26 mm (range, 15-43 mm). The height and length of the calcaneus were restored nearly to the same as the opposite foot. The mean preoperative calcaneal pitch angle increased from 2.6 degrees to an average of 19.0 degrees after the surgery. The AOFAS score increased from 60.0 to 86.0. One patient experienced pin infection. The infection healed after changing the dressing. Calcaneal lengthening using an Ilizarov external fixator is a preferable technique to restore the length and height of the calcaneus and can achieve satisfactory foot function.

Analysis of risk factors for nonunion in pediatric lateral column lengthening

The lateral column lengthening procedure is a commonly used osteotomy for correction of pes planus performed by inserting a graft in the anterior aspect of the calcaneus through a transverse osteotomy. Though nonunion and calcaneo-cuboid subluxation have been previously reported, these complications have not been extensively studied in pediatric patients. After IRB approval, 111 patients (151 feet) who underwent lateral column lengthening at a single institution were identified. Fifty-three females (70 feet) and 58 males (81 feet) with an average age of 11.4 years (2.6 SD; range 5-17) were analyzed. The primary outcome was nonunion defined as a lack of radiographic evidence of osteotomy healing by 9 months. Underlying diagnosis, pre and postoperative radiographic measurements, age, operative technique, fixation, calcaneo-cuboid subluxation, graft material and concomitant procedures were analyzed for their relationship to nonunion. Nonunion occurred in 7 of 151 feet (4.6%). Patient age at the time of surgery and calcaneo-cuboid subluxation trended toward a significant association with nonunion ( P  = 0.053, 0.054, respectively). The degree of surgical correction, as determined by radiographic analysis, and the use of calcaneo-cuboid fixation were not significantly associated with nonunion. None of the other factors evaluated were significantly associated with nonunion. There were three cases of postoperative infections (2.0%), two were superficial and 1 (0.7%) was deep. Thirty-five of 151 feet disclosed radiographic evidence of subluxation. Excluding subluxation, the overall complication rate was 8.6%. Nonunion occurred in 4.6% of pediatric feet undergoing lateral column lengthening. Fixation type was not significantly associated with nonunion. Older age at the time of surgery and calcaneocuboid subluxation trended towards significance. The placement of a calcaneo-cuboid pin was not found to be a significant factor in preventing calcaneo-cuboid subluxation or nonunion.

Lateral column lengthening (LCL) using a rectangular shape graft for managing symptomatic flexible flatfoot showed acceptable early functional and radiological outcomes

PURPOSE

We aimed to report the results of performing lateral column lengthening (LCL) using a rectangular-shaped graft to correct the flat foot deformity.

METHODS

A total of 28 feet of 19 patients (10 males, 9 females) having an average age of 10 ± 3.2 years who were unresponsive to conservative management underwent flat foot deformity correction through LCL procedure supplemented with rectangular-shaped graft harvested from the fibula. Functional assessment was performed according to the American Orthopedic Foot and Ankle Society (AOFAS) scale. The radiographic assessment consisted of four parameters, Meary's angle in both anteroposterior (AP) and lateral (Lat.) views, calcaneal inclination angle (CIA), and calcaneocuboid angle (CCA).

RESULTS

After an average of 30.2 ± 8.1 months, the AOFAS improved significantly from 46.7 ± 10.2 preoperatively to 86.7 ± 9.5 at the last follow up (P < 0.05). All the osteotomies showed healing at an average of 10.3 ± 2.7 weeks. All the radiological parameters showed significant improvement at the last follow up compared to the preoperative measurements, CIA from 6.3 ± 2.8-19.3 ± 3.5, Lat. Meary's angle from 19.3 ± 4.9-5.8 ± 2.5, AP Meary's Angle from 19.3 ± 5.8-6.1 ± 3.1, and CCA from 23.9 ± 8.2-6.8 ± 4.5, (P < 0.05). No pain at the site of the fibular osteotomy was reported in any of the patients.

CONCLUSION

Lateral column lengthening using a rectangular graft effectively restores bony alignment with good radiological and clinical results, high patient satisfaction, and acceptable complications.

Osteoclast-Driven Osteogenesis, Bone Remodeling and Biomaterial Resorption: A New Profile of BMP2-CPC-Induced Alveolar Bone Regeneration

This bedside-to-bench study aimed to systematically investigate the value of applying BMP2-loaded calcium phosphate cement (BMP2-CPC) in the restoration of large-scale alveolar bone defects. Compared to deproteinized bovine bone (DBB), BMP2-CPC was shown to be capable of inducing a favorable pattern of bone regeneration and bone remodeling accompanied by active osteoclastogenesis and optimized biomaterial resorption when applied in reconstructive periodontally accelerated osteogenic orthodontics (PAOO) surgery. To verify the regulatory role of osteoclasts in the BMP2-CPC-induced pattern of bone regeneration, in vitro and in vivo studies were designed to elucidate the underlying mechanism. Our results revealed that osteoclasts played a multifaceted role (facilitating osteogenesis, bone remodeling and biomaterial resorption) in the BMP2-CPC-induced bone regeneration. Osteoclasts contributed to the osteogenic differentiation of mesenchymal stem cells (MSCs) by secreting calcium ions, CTHRC1 and PDGF-B. Moreover, the increased osteoclasts promoted the remodeling of new bone and BMP2-CPC resorption, leading to a harmonized replacement of biomaterials with mature bone. In conclusion, the in vitro and in vivo experimental results corresponded with the clinical results and showed the optimized properties of BMP2-CPC in activating osteoclast-driven bone regeneration and remodeling, thus indicating the highly promising prospects of BMP2-CPC as an ideal therapeutic for alveolar bone defects.

Calcaneal lengthening using ipsilateral fibula autograft in the treatment of symptomatic pes valgus in adolescents

Background

Evans calcaneal lengthening osteotomy is used to treat symptomatic flexible flatfoot when conservative treatment fails. Grafts such as autologous iliac bone grafts, allografts, and xenografts are implanted at the osteotomy site to lengthen the lateral column of the hindfoot. This study aimed to present the outcomes of an autologous mid-fibula bone graft used for calcaneal lengthening in symptomatic pes valgus in adolescents.

Methods

We retrospectively examined 23 ft of 13 adolescents who underwent surgery between July 2014 and January 2018. The radiological and clinical outcomes (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale scores) were assessed during a mean follow-up of 49.7 (range, 30.9–73.4) months. The mean distance of the lengthening site was measured to evaluate graft sinking or collapse. The Goldberg scoring system was used to determine the degree of union at the donor and recipient sites.

Results

The calcaneal pitch and the anteroposterior and lateral talo-first metatarsal (Meary) angles showed significant correction, from 14.4 to 19.6 (p < 0.001), and from 14.5 to 4.6 (p < 0.001) and 13.5 to 8.5 (p < 0.001), respectively. The mean distance of the lengthening site showed no significant change (p = 0.203), suggesting no graft sinking or postoperative collapse. The lateral distal tibial angle showed no significant difference (p = 0.398), suggesting no postoperative ankle valgus changes. Healing of the recipient and donor sites occurred in 23 and 21 ft, respectively. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scores improved significantly, from 68.0 to 98.5 (p < 0.001).

Conclusions

Evans calcaneal lengthening using an ipsilateral mid-fibula bone autograft resulted in significant improvement in clinical and radiological outcomes without ankle valgus deformity. Hence, it could be a treatment option for lateral column calcaneal lengthening in adolescents.

Subtalar distraction arthrodesis for calcaneal malunion - comparison of structural freeze-dried versus autologous iliac bone graft

BACKGROUND

This study aims to analyze the outcomes of subtalar distraction arthrodesis (SDA) for calcaneal malunion using structural freeze-dried iliac allograft (FDIA) compared to using autologous iliac bone (AIB).

METHODS

We retrospectively evaluated 57 consecutive cases (51 patients) of calcaneal malunion between March 2006 and December 2017. All patients were followed for an average of 22.8 months. All cases were treated by SDA using structural FDIA (17 cases, group 1), or AIB (40 cases, group 2). The outcome measures included the American Orthopaedic Foot and Ankle Society ankle-hindfoot (AOFAS) scores, visual analog scale (VAS) pain scores, and radiographic measurements.

RESULTS

The mean postoperative 3, 6, and 12 months of AOFAS scores and VAS pain score were significantly better in group 2 than those in group 1 (p < 0.05, for all). There were 3 cases (17.6%) of nonunion in the group 1, whereas the group 2 had 2 cases (5.0%), which did not shown significant difference between two groups (p = 0.492). Although the mean pre-, postoperative, and final follow-up radiologic parameters in both groups were similar, (p > 0.05, for all) the difference of talocalcaneal height, talocalcaneal angle, and talar declination angle from postoperative to final follow-up were significantly bigger in the group 1. (p < 0.05, for all).

CONCLUSION

Although union rate was not significantly different between the two groups, we obtained more favorable clinical and radiologic outcomes in the autologous iliac bone group. Using FDIA without any orthobiological agent for SDA, there were significant more loss of radiological parameters due to inferior incorporation and biomechanical properties. When considering the SDA for calcaneal malunion, routine use of FDIA without any orthobiological agents as an interpositional graft for SDA is not recommended.

Radiographic changes of the mid-tarsal joint after calcaneal lengthening for planovalgus foot deformity

BACKGROUND

This study evaluate the radiographic changes in the mid-tarsal joint, including the calcaneocuboid and talonavicular (TN) joints after calcaneal lengthening for planovalgus deformity in children.

METHODS

This study included 38 patients (68 feet) who underwent calcaneal lengthening for planovalgus deformity. Radiographic osteoarthritic changes at the CC or TN joint were defined as modified Kellgren-Lawrence grade of ≥1.

RESULTS

Among the 68 feet, 31 feet (45.6%) showed radiographic osteoarthritic changes at the CC joint and 20 (29.4%) showed changes at the TN joint. Risk of radiographic osteoarthritic changes at the CC joint was associated with increased age at surgery (OR = 1.2, p = 0.038). Risk of radiographic osteoarthritic changes at the TN joint was associated with increased age at surgery (OR = 2.2; p = 0.002), preoperative AP talus-1st metatarsal angle (OR = 1.1; p = 0.044), and degree of CC subluxation (OR = 2.1; p = 0.007).

CONCLUSIONS

Surgeons should consider the risk factors in the surgical correction of planovalgus deformity to prevent mid-tarsal arthritis.

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Surgical treatment of idiopathic pes planovalgus in paediatric patients

Idiopathic pes planus is common and usually physiologic. Decompensation, when it occurs, may be obvious or on the contrary difficult to identify, raising challenges in patient selection for surgical treatment. The physical examination of a child with pes planus must include an evaluation in the supine position, which helps to adjust the amount of correction during surgery. The many reported surgical procedures include repositioning (talus-reseating, subtalar implants and calcaneo-stop screw), osteotomies and joint fusions. The primary treatment goal is to achieve full architectural correction of the deformity. Selection of the procedure depends on patient age and reducibility of the deformity. The joint lines should be preserved whenever possible. Triceps surae contracture should be sought and corrected if found.

Lateral column lengthening versus subtalar arthroereisis for paediatric flatfeet: a systematic review

PURPOSE

This systematic review aimed to compare radiographic correction, clinical outcomes, complications, and re-operations between lateral column lengthening (LCL) and arthroereisis (AR) for treating symptomatic flatfoot in children.

METHODS

We conducted a comprehensive search on MEDLINE, EMBASE, and Cochrane Library databases. Literature search, data extraction, and quality assessment were conducted by two independent reviewers. The outcomes analyzed included radiographic parameters, clinical scores, satisfaction, complications, and re-operations.

RESULTS

Twenty-one and 13 studies were included in the LCL and AR groups, respectively. The change in anteroposterior talo-first metatarsal angle was greater in the LCL (9.5° to 21.7°) than in the AR group (10.6° to 12.8°). The change in calcaneal pitch was greater in the LCL (2.1° to 26.53°) than in the AR group (- 1.3° to 3.23°). Improvements in the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were greater in the LCL (27.7 to 39.1) than in the AR group (17 to 22). The percentage of satisfaction was similar between the LCL (68% to 89%) and AR (78.5% to 96.4%) groups. The complication rate was higher in the LCL (0% to 86.9%) than in the AR group (3.5% to 45%). The most common complications were calcaneocuboid subluxation and persistent pain in the LCL and AR groups, respectively. The re-operation rate was similar between the LCL (0% to 27.3%) and AR (0% to 36.4%) groups.

CONCLUSIONS

The LCL group has achieved more radiographic corrections and more improvements in the AOFAS score than the AR group. Complications were more common in the LCL group than in the AR group, and the re-operation rates were similar between the two groups.

Use of iliac crest allograft for Dega pelvic osteotomy in patients with cerebral palsy

Background

Dega pelvic osteotomy is commonly performed procedure in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for hip displacement. However, there has been no study investigating the outcomes after Dega pelvic osteotomy using allograft in patients with CP. This study investigated the outcomes of Dega pelvic osteotomy using iliac crest allograft in CP with hip displacement and the factors affecting allograft incorporation.

Methods

This study included 110 patients (150 hips; mean age 8y7mo; 68 males, 42 females) who underwent hip reconstructive surgeries including Dega pelvic osteotomy using iliac crest allograft. To evaluate the time of allograft incorporation, Goldberg score was evaluated according to the follow-up period on all postoperative hip radiographs. The acetabular index, migration percentage, and neck-shaft angle were also measured on the preoperative and postoperative follow-up radiographs.

Results

The mean estimated time for allograft incorporation (Goldberg score ≥ 6) was 1.1 years postoperatively. All hips showed radiographic union at the final follow-up and there was no case of graft-related complications. Patients with Gross Motor Function Classification System (GMFCS) level V had 6.9 times higher risk of radiographic delayed union than those with GMFCS level III and IV. Acetabular index did not increase during the follow-up period (p = 0.316).

Conclusions

Dega pelvic osteotomy using iliac crest allograft was effective in correcting acetabular dysplasia, without graft-related complications in patients with CP. Furthermore, the correction of acetabular dysplasia remained stable during the follow-up period.

Undercorrection of planovalgus deformity after calcaneal lengthening in patients with cerebral palsy

Calcaneal lengthening (CL) is one of the treatment options for planovalgus deformity in patients with cerebral palsy (CP). However, its indication still needs to be clarified according to the functional status of CP. The aim of this study was to investigate the radiographic outcome after CL in patients with CP and to evaluate the risk factors causing undercorrection of planovalgus deformities. We included consecutive patients with CP who underwent CL for planovalgus deformity, were followed for more than 2 years, and had preoperative and postoperative weight-bearing anteroposterior (AP) and lateral foot radiographs. Six radiographic indices were used to assess the radiographic outcome. The patient age, sex, and Gross Motor Function Classification System (GMFCS) level were evaluated as possible risk factors, and we controlled for the interaction of potentially confounding variables using multivariate analysis. A total of 44 (77 feet) patients were included in this study. The mean age of the patients at the time of surgery was 10.5±4.0 years and the mean follow-up was 5.1±2.2 years. Patients with GMFCS III/IV achieved less correction than those with GMFCS I/II in the AP talus-first metatarsal angle (P=0.001), lateral talocalcaneal angle (P=0.028), and the lateral talus-first metatarsal angle (P<0.001). The rate of undercorrection in the GMFCS III/IV group was 1.6 times higher than that in the GMFCS I/II group in the AP talus-first metatarsal angle (odds ratios: 1.6; 95% confidence interval: 1.2-2.0; P<0.001) and 1.6 times higher in the lateral talus-first metatarsal angle (odds ratios: 1.6; 95% confidence interval: 1.3-1.9; P<0.001). In GMFCS I/II patients with CP, we found CL to be an effective procedure for the correction of planovalgus foot deformities. However, in GMFCS III/IV patients with planovalgus deformities, CL appears to be insufficient on the basis of the high rate of undercorrection in these patients. For patients with GMFCS level III/IV, additional or alternative procedures should be considered to correct the deformity and maintain the correction achieved.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is structural hydroxyapatite tricalcium-phosphate graft or tricortical iliac crest autograft better for calcaneal lengthening osteotomy in childhood? interim results from a randomised, controlled non-inferiority study

AIMS

To compare the structural durability of hydroxyapatite-tricalcium phosphate (HATCP) to autologous iliac crest bone graft in calcaneal lengthening osteotomy (CLO) for pes planovalgus in childhood.

PATIENTS AND METHODS

We present the interim results of ten patients (HATCP, n = 6 and autograft, n = 5) with a mean age of 11.5 years (8.2 to 14.2) from a randomised controlled non-inferiority trial with six months follow-up. The primary outcome was the stability of the osteotomy as measured by radiostereometric analysis. A non-inferiority margin of ≤ 2 mm osteotomy compression was set.

RESULTS

At six months the data showed that the osteotomy had been compressed by a mean 1.97 mm (99.8% confidence interval -1.65 to 5.60) more in the HATCP group than in the autograft group. Migration of the CLO grafted with HATCP stabilised at six months rather than at six weeks with autograft.

CONCLUSION

This is the first randomised trial to compare the efficacy of HATCP graft with autograft in terms of stability of CLO in children. Because of problems with the HATCP the trial was stopped. We do not recommend HATCP graft in its current structure for use in unfixed CLOs. Cite this article: Bone Joint J 2016;98-B:1554-62.

Fabrication and clinical application of easy-to-operate pre-cured CPC/rhBMP-2 micro-scaffolds for bone regeneration

Bone tissue engineering scaffolds loading growth factors have been considered as the most perspective among all bone substitutes, yet little progress of its clinical translation has been made. The concept of "micro-scaffolds" was proposed in this study to provide a trajectory to the clinical translation of porous scaffolds. Combining CPC and rhBMP-2, a pre-cured CPC/rhBMP-2 micro-scaffold has been successfully developed and further applied as an easy-to-operate filler for bone regeneration in a pilot clinical study. The results demonstrated superior overall performances of CPC/rhBMP-2 microffolds to traditional therapies, with not only shortened repairing time and improved repairing qualities, but also the potential in treating fractures that are most challenging for current therapies. This pilot clinical study of CPC/rhBMP-2 microffolds further promoted the clinical translation of porous scaffolds for bone regeneration, and provided new insights for future development of artificial bone substitutes.

An injectable nano-hydroxyapatite (n-HA)/glycol chitosan (G-CS)/hyaluronic acid (HyA) composite hydrogel for bone tissue engineering

The aim of the present study was to fabricate an injectable nano-hydroxyapatite (n-HA)/glycol chitosan (G-CS)/hyaluronic acid (HyA) composite hydrogel and investigate its potent application in bone tissue engineering.